The present invention relates to an automatic chemical or biochemical analysis apparatus for automatically measuring a quantity of a specific chemical or biochemical substance contained in a material to be analized and, more particularly, to a nozzle-type analysis apparatus adapted to measure a trace quantity of material to be analized such as blood specimen.
Recently, in a biochemical automatic analysis apparatus for automatically measuring a quantity of a specific chemical substance contained in a material to be analized such as blood specimen, it has been required to inspect many kinds of inspection items, to reduce a quantity of a material required, to improve an inspection speed and the like.
In order to satisfy these requirement, one measure is to minimize an order of quantity of the material to be measured for one inspection item such as to 1 micron (1.mu.) order. One conventional biochemical automatic analysis apparatus has such a structure as shown in Figs. 10 and 11. Referring to FIGS. 10 and 11, A blood serum S as a sample to be analyzed is stored in a primary vessel 2 supported by a sample disc 1, and a plurality of primary sample vessels 2 are generally supported by the disc 1.
An automatic analysis of the blood serum sample S contained in the primary sample vessel 2 is perfomed by first sampling the blood serum sample S from the primary sample vessel 2 by means of a sampling nozzle 3 and then delivering the sample S into a sample vessel 4. A plurality of sample vessels 4 are disposed to a reaction disc 5 and necessary reagent or reagents are then delivered into the respective sample vessels 4 through a reagent delivering nozzle 8 from reagent vessels 7 supported by a reagent disc 6.
After the addition of the reagent into the sample vessels 4, an analyzer light is irradiated to the respective sample vessels 4 through an optical measurement system 9 to thereby carry out an absorption analysis, and on the while, as shown in FIG. 11, the blood serum sample S in the sample vessel 4 is sucked by a sample suction nozzle 10 for an electrolyte measurement and then supplied to a flow-through type ion sensor system 11 for the electrolyte measurement as a nozzle-type analysis apparatus, thus performing an electrolyte analizing operation.
FIG. 11 represents the flow-through type ion sensor system 11 as one example of a conventional electrolyte measurement system performing the electrolyte analysis. Referring to FIG. 11, the blood serum sample S is sucked, by immersing the front end of the sample suction nozzle 10 communicated with a flow cell 12 into the sample vessel 4 supported by the reaction disc 5, into the flow cell 12 of the ion sensor system 11 from the sample vessel 4. The flow cell 12 is accommodated in a constant temperature jacket 13 for keeping constant temperature of each sensor disposed in the flow cell 12 and the blood serum sample S by circulating hot water of constant temperature in the constant temperature jacket 13 through a constant temperature water circulation system 14. A signal from each sensor disposed in the flow cell 12 is transmitted externally to thereby carry out the electrolyte analysis.
In FIG. 10, the automatic analysis system includes a washing unit 16 for the sample vessels, a sampling nozzle arm 17, a reagent nozzle arm 18, a black box 19a of the optical measurement system 9 and a light source 19b.
In the conventional flow-through type ion sensor system 11 of the structure described above, the sample suction nozzle 10 is directly immersed or dipped into the blood serum sample S in the sample vessel 4 to suck the sample and supply it into the flow cell 12 by means of the sample suction nozzle 10. According to this ion sensor system 11, the sample suction nozzle 10 has a nozzle portion having a relatively long length extending between the sample vessel 4 and the flow cell 12. This involves a problem of requiring an extra quantity of blood serum sample solution corresponding to an inner volume of this nozzle portion. Furthermore, an extremely large quantity of blood serum sample is required for the electrolyte measurement in comparison with other inspection or analysis items, so that reduction of the quantity of the sample to be used for the electrolyte measurement has been desired for achieving necessary trace quantity analysis.
Still furthermore, although the temperature of the sample vessel 4 is maintained to the constant temperature of 37.degree. by a constant temperature tank, not shown, disposed below the reaction disc 5, it is difficult to maintain a temperature in an upper space, in which the suction nozzle arm and others are elevated, to the constant temperature. In order to obviate this defect, it is necessary to locally dispose the constant temperature jacket 13 to the flow cell positioned at the upper end of the material suction nozzle 10, resulting in the location of a specific temperature control system or hot water-circulation system 14, making complicated the electrolyte measurement system itself and making difficult to exchange a sensor cell.
Although the trace quantity analysis of the sample to be analized may be performed by making small an inner diameter of a sample flow passage, the reduction of the inner diameter will results in a lowering of a conductance of the sample flow passage, which hence results in a time lag between the sucking operation of a sample suction pump, not shown, disposed with a space along the sample flow passage and an actual sample sucking operation, thus being inconvenient.
Moreover, according to this time lag, so-called a trailing phenomenon of the sample solution is caused after the stopping of the operation of the suction pump and the stabilization of an output is hence delayed, resulting in the slow-down of a treating speed. In order to avoid this problem of the trailing phenomenon, the sample suction nozzle 10 may be maintained in a state immersed in the sample solution S, but in this state, the flow cell sensor likely picks up noises from a solution surface of the sample solution S. This will results in degradation of the measurement performance.